There are so many alarmist statements in the article where to start? Best to lower all the speed limits to zero and take the train.
How about we test removing speed limits all together? They are arbitrary anyways based on best road conditions, and for the majority of vehicles and vehicle types that use the road.
How would a limitless road work? Instead of fining for speed we fine for hitting other vehicles (Rule 1: don't hit things), being a douchbag (Rule 2: be courteous and respect rules of the road, like not driving in the left lane from trip start to finish, merging properly and allowing vehicles to merge), driving too fast for conditions - which would include driving way to fast down a crowded city street, if you have no chance to react to pedestrians or bikers or whatever, you are going to fast.
(for extra credit: for all you that think driving 55mph/90kph should be the maxium because of fuel economy, think of the lives that are lost because drivers fall asleep because they are bored, or start texting because they are bored. Driving faster increases excitement and the involvement of the driver. Lord forbid we actually have some fun.)